The present invention relates to batteries and more particularly to battery cells having nickel electrodes. In one aspect, this invention relates to novel nickel electrodes; in another aspect it relates to a method for fabricating nickel electrodes.
Large shear stresses exist in sintered nickel hydroxide electrodes. The principal cause of these stresses is the mechanical inhomogeneity introduced by the electrode current collectors, which are substantially more rigid than the nickel sinter, and the molar volume change of the acitve materials during charge and discharge. The shear stresses have been shown to cause fracturing of the electrode at the sinter-collector interface which, in turn, has been related to electrode blistering.
Shear failure can be reduced by incorporating additives, such as cobalt hydroxide, into the electrode. Cobalt, however, is becoming more scarce and higher in cost; thus some manufacturers have reduced the level of cobalt in their nickel electrodes.
Work has been done with gridless electrodes, i.e., electrodes without the current collector. Although gridless electrodes appear to be free of shear stresses, their inherently fragile nature may limit their uses to experimental purposes only.
It is an object of the present invention to provide a low shear electrode plaque.
It is another object to provide a low shear nickel electrode.
Further objects of the present invention include methods for the fabrication of the above plaque and electrode.
Other objects, aspects and advantages of the present invention will become apparent to those skilled in the art upon consideration of the accompanying disclosure.